Method for isolating cellulose from a biomass and products provided therefrom

ABSTRACT

A pretreated biomass is subjected to high frequency pulses and shear forces without denaturing and/or degrading the individual components of the biomass. The biomass is then subjected to compressive force to separate a first liquid fraction from a first fractionated biomass. The first fractionated biomass may again then be subjected to the same high frequency pulses and shear forces as previously, particularly if there are hemicellulose and/or sugars still present in the first fractionated biomass. Compressive forces are used to separate a second liquid fraction from a second fractionated biomass. The second fractionated biomass is subjected to oxidation. The second fractioned biomass is then subjected to compressive forces to separate out one or more water insoluble components of the biomass in water soluble form and to provide cellulose that has not been denatured and/or degraded and has a lignin contact of less than 7 percent.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. application Ser. No.14/454,972, filed Aug. 8, 2014, which claims priority to U.S.Provisional Patent Application Ser. No. 61/864,853, filed Aug. 12, 2013,U.S. Provisional Patent Application Ser. No. 61/909,418, filed Nov. 27,2013, and U.S. Provisional Patent Application Ser. No. 61/919,194, filedDec. 20, 2013, the disclosures of which are incorporated herein byreference in their entirety.

FIELD OF THE INVENTION

The present invention relates to a process for isolating components of abiomass. Examples of fractions and extractives provided in the processinclude the extraction, isolation, and purification of lignin,cellulose, sugars, hemicellulose, fibers and/or extractives.

BACKGROUND OF THE INVENTION

Natural cellulosic feedstocks are typically referred to as “biomass.”Many types of biomass, including wood, paper, agricultural residues,herbaceous crops, and lignocellulosic municipal and industrial solidwastes have been considered as feedstocks for the production andpreparation of a wide range of goods. Plant biomass materials arecomprised primarily of cellulose, hemicellulose and lignin, boundtogether in a complex and entangled gel-like structure along withamounts of extractables, pectins, proteins and/or ash. Thus, successfulcommercial use of biomass as a chemical feedstock depends on theefficient and/or economical separation and isolation of these variousconstituents.

Many steps are often required in production, harvesting, storage,transporting, and processing of biomass to yield useful products. Onestep in the processing is the separation, or fractionation, of thebiomass into its major components: extractives, hemicellulose, lignin,and cellulose with smaller amounts of pectins, ash, protein, and cutin.Many approaches have been investigated for disentangling the complexstructure of the biomass. Once this separation has been achieved, avariety of paths are opened for further processing of each componentinto marketable products. For example, the possibility of producingproducts such as biofuels, polymers and latex replacements from biomasshas recently received much attention. This attention is due to theavailability of large amounts of cellulosic feedstock, the need tominimize burning or landfilling of waste cellulosic materials, and theusefulness of sugar and cellulose as raw materials substituting foroil-based products.

One component of the biomass that the isolation of which has been ofinterest is cellulose. Cellulose, particularly delignified cellulose isof particular interest to the paper industry and in the production ofbiofuels. Cellulose is an organic compound with the formula(C₆H₁₀O₅)_(n), a polysaccharide consisting of a linear chain of severalhundred to over ten thousand β(1→4) linked D-glucose units. Cellulose isan important structural component of the primary cell wall of greenplants, many forms of algae and the oomycetes. Cellulose is an extremelyabundant organic polymer on Earth. The cellulose content of cotton fiberis 90%, that of wood is 40-50% and that of dried hemp is approximately45%. Cellulose is mainly used to produce paperboard and paper. Smallerquantities are converted into a wide variety of derivative products suchas cellophane and rayon. Using cellulose as a feedstock can beproblematic if the cellulose has been denaturated and/or degraded due toharsh conditions such as high temperature, high pressure chemicalexposure, high acidic conditions and/or high basic conditions.

Thus, there continues to be a need for improved systems and methods forproviding cellulose and cellulose substantially devoid of lignin,hemicellulose, other sugars and ash that take into consideration factorssuch as environmental and energy concerns, efficiency andcost-effectiveness, while limiting the denaturating and/or degrading ofthe cellulose composition.

SUMMARY OF THE INVENTION

It should be appreciated that this Summary is provided to introduce aselection of concepts in a simplified form, the concepts being furtherdescribed below in the Detailed Description. This Summary is notintended to identify key features or essential features of thisdisclosure, nor is it intended to limit the scope of the invention.

The present invention provides a process for isolating cellulose thatmay be adapted to large-scale production, uses environmentally friendlysolvents and/or is energy efficient. Moreover, the present inventionprovides a process for isolating and delignifying cellulose wherein thecellulose is substantially devoid of lignin, hemicellulose, othersugars, and various other water insoluble components, while maintainingits structure substantially similar to that of it in the biomass.

The process includes subjecting the biomass to conditions to isolate thecellulose from the biomass in a non-denaturated or non-degraded form andthen subjecting the cellulose to oxidation to remove any remaininghemicelluloses, lignin, and the like to purify the cellulose fraction.The process includes pretreating the biomass to, for example, remove asubstantial portion of the hemicellulose component. Pretreatment mayinclude mechanically altering the fibers to, for example, open up thefibers and to form a fluidized biomass. The biomass with opened upfibers is then subjected to high frequency pulses and shear forceswithout denaturing the individual components of the biomass. The biomassis then subjected to compressive force to separate a first liquidfraction from a first fractionated biomass. The first fractionatedbiomass may again then be subjected to the same high frequency pulsesand shear forces as previously, particularly if there are hemicelluloseand/or sugars still present in the first fractionated biomass.Compressive forces are used to separate a second liquid fraction from asecond fractionated biomass. The second fractionated biomass is high incellulose and water insoluble components including lignins and proteins,and is substantially devoid of hemicelluloses and sugars. The secondfractionated biomass is subjected to oxidation. The second fractionedbiomass is then subjected to compressive forces to separate one or morewater insoluble components of the biomass in water soluble and liquidform from a second fractionated biomass high in cellulose andsubstantially devoid of hemicellulose, sugar and the water insolublecomponents of the biomass, particularly lignin.

The cellulose of the second fractionated biomass is not denatured ordegraded, i.e., it is substantially similar to the cellulose in thebiomass prior to isolation. It is believed that because the process ofthe present invention avoids high temperature, high pressure, extremechemical conditions, high acidic or basic conditions, and the like,denaturing and/or degrading the cellulose is avoided and provides thedelignified cellulose in a form particularly suitable as a feedstock.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a flow chart that outlines an embodiment of the processof the invention.

FIG. 2 depicts a flow chart that outlines another embodiment of theprocess of the invention.

FIGS. 3A and 3B depict various DSCs taken on the third fractionatedbiomass of Example 2.

DETAILED DESCRIPTION OF EMBODIMENTS

In the following detailed description, embodiments of the presentinvention are described in detail to enable practice of the invention.Although the invention is described with reference to these specificembodiments, it should be appreciated that the invention can be embodiedin different forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the invention to those skilled in the art.

The terminology used in the description of the invention herein is forthe purpose of describing particular embodiments only and is notintended to be limiting of the invention. As used in the description ofthe invention and the appended claims, the singular forms “a,” “an” and“the” are intended to include the plural forms as well, unless thecontext clearly indicates otherwise. The invention includes numerousalternatives, modifications, and equivalents as will become apparentfrom consideration of the following detailed description.

It will be understood that although the terms “first,” “second,”“third,” “a),” “b),” and “c),” etc. may be used herein to describevarious elements of the invention should not be limited by these terms.These terms are only used to distinguish one element of the inventionfrom another. Thus, a first element discussed below could be termed aelement aspect, and similarly, a third without departing from theteachings of the present invention. Thus, the terms “first,” “second,”“third,” “a),” “b),” and “c),” etc. are not intended to necessarilyconvey a sequence or other hierarchy to the associated elements but areused for identification purposes only. The sequence of operations (orsteps) is not limited to the order presented in the claims or figuresunless specifically indicated otherwise. Steps may be conductedsimultaneously.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this invention belongs. It will befurther understood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the present applicationand relevant art and should not be interpreted in an idealized or overlyformal sense unless expressly so defined herein. The terminology used inthe description of the invention herein is for the purpose of describingparticular embodiments only and is not intended to be limiting of theinvention. All publications, patent applications, patents and otherreferences mentioned herein are incorporated by reference in theirentirety. In case of a conflict in terminology, the presentspecification is controlling.

Also as used herein, “and/or” refers to and encompasses any and allpossible combinations of one or more of the associated listed items, aswell as the lack of combinations when interpreted in the alternative(“or”).

Unless the context indicates otherwise, it is specifically intended thatthe various features of the invention described herein can be used inany combination. Moreover, the present invention also contemplates thatin some embodiments of the invention, any feature or combination offeatures set forth herein can be excluded or omitted. To illustrate, ifthe specification states that a complex comprises components A, B and C,it is specifically intended that any of A, B or C, or a combinationthereof, can be omitted and disclaimed.

As used herein, the transitional phrase “consisting essentially of” (andgrammatical variants) is to be interpreted as encompassing the recitedmaterials or steps “and those that do not materially affect the basicand novel characteristic(s)” of the claimed invention. See, In re Herz,537 F.2d 549, 551-52, 190 U.S.P.Q. 461, 463 (CCPA 1976) (emphasis in theoriginal); see also MPEP §2111.03. Thus, the term “consistingessentially of” as used herein should not be interpreted as equivalentto “comprising.”

The term “about,” as used herein when referring to a measurable value,such as, for example, an amount or concentration and the like, is meantto encompass variations of ±20%, ±10%, ±5%, ±1%, +0.5%, or even ±0.1% ofthe specified amount. A range provided herein for a measurable value mayinclude any other range and/or individual value therein.

The term “biomass” includes any non-fossilized, i.e., renewable, organicmatter. The various types of biomass may include plant biomass, animalbiomass (any animal by-product, animal waste, etc.) and municipal wastebiomass (residential and light commercial refuse with recyclables suchas metal and glass removed).

The term “plant biomass” or “ligno-cellulosic biomass” includesvirtually any plant-derived organic matter (woody or non-woody)available for energy on a sustainable basis. “Plant-derived” necessarilyincludes both sexually reproductive plant parts involved in theproduction of seed (e.g., flower buds, flowers, fruit, nuts, and seeds)and vegetative parts (e.g., leaves, roots, leaf buds and stems). Plantbiomass can include, but is not limited to, agricultural crop wastes andresidues such as corn stover, wheat straw, rice straw, sugar canebagasse and the like. Plant biomass further includes, but is not limitedto, woody energy crops, wood wastes and residues such as trees, softwoodforest thinnings, barky wastes, sawdust, paper and pulp industry wastestreams, wood fiber, herbal plant material brewing wastes, and the like.Additionally grass crops, such as switchgrass and the like have thepotential to be produced in large-scale amounts and to provide asignificant source of another plant biomass. For urban areas, potentialplant biomass feedstock comprises yard waste (e.g., grass clippings,leaves, tree clippings, brush, etc.) and vegetable processing waste.

The biomass comprises three basic chemical components/fractions, namelyhemicellulose, cellulose, and lignins. The biomass may also includelesser amounts of proteins, extractives, pectins, cutin, and ashdepending on the biomass. Specifically, hemicellulose is a polymer(matrix polysaccharide) comprising the pentose and hexose sugars xylon,glucuronoxylon, arabinoxylon, glucomannon, and xyloglucan. The sugarsare highly substituted with acetic acid, and because of its branchedstructure, hemicellulose is amorphous. Hemicellulose is also easy tocleave via hydrolysis. In contract, cellulose is a linear polymer(polysaccharide) of glucose sugars bonded together by β-glycosidiclinkages to form lengthy linear chains. Hydrogen bonding can occurbetween cellulose chains results in a rigid crystalline structure whichis resistant to cleavage. Lignin is a polymer of phenolic molecules andis hydrophobic. It provides structural integrity to plants, i.e., it isthe glue that maintains the plant intact.

Typical ranges of hemicellulose, cellulose, and lignin in, for example,a plant biomass such as corn stover are:

Component Biomass Dry Weight Cellulose 30-50% Hemicellulose 20-40%Lignin 10-25%

“Ambient temperature” includes the temperature of the surroundings inwhich the process of the invention takes place. Ambient temperature mayinclude, but is not limited to, “room temperature,” and any temperaturewithin the range of about 0 to about 40° C. (30 to 104° F.).

Individual components of the biomass may include, but are not limitedto, lignin, cellulose, hemicellulose, others sugars, proteins,pharmaceuticals, nutraceuticals, ash, pectins and cutin, and othermaterials obtained from the leaves, stems, flowers, buds, roots, tubers,seeds, nuts, fruit and the like of a plant.

“Alcohol” includes, but is not limited to, methanol, ethanol,isopropanol, propanol, isobutanol, butanol, and glycol. A “short chainalcohol” generally includes C₁ to C₄ alcohols.

“Water” includes, but is not limited to, deionized water, spring water,distilled water, mineral water, tap water and well water, and mixturesthereof. “Water soluble” includes a component that can be dissolved inwater or other solvent at ambient temperature. “Water insoluble”includes a component that cannot be dissolved in water or other solventat ambient temperature.

Referring now to FIG. 1, operations for the fractionation and extractionof various biomasses, according to some embodiments of the presentinvention, will be described. A pretreatment step 90 may be conductedoptionally at ambient temperature. The biomass may be subjected to apre-soak step 100 and/or disassembly step 110. The disassembly step 110may include mechanical disassembling of the biomass to provide thebiomass in a fluidized or flowable state or condition. The pre-soak step100 may include contacting with a solvent with or without additives tofacilitate the separation of the individual components. In anotherembodiment, the pretreatment step may include hydrolysis (orrehydrolysis of biomass in dried condition) to about 20 to 50 percentmoisture gain. The hydrolysis may be accomplished by treating thebiomass with steam. The pretreated biomass may then be subjected to aseparation step 105 using conventional separation techniques such asusing ultrafiltration or diafiltration membranes. After the pretreatmentstep 90, the biomass may be subjected to high frequency pulses and highshear forces to fractionate 120 or extract via, for example, the biomassfractionation apparatus and methods described in co-pending U.S. patentapplication Ser. No. 14/454,833, filed on Aug. 8, 2014 (Attorney DocketNo. 1237-3) and co-pending U.S. patent application Ser. No. 14/454,952,filed on Aug. 8, 2014 (Attorney Docket No. 1237-2), the disclosures ofwhich are incorporated by reference in their entireties. Suchfractionation does not denature and/or degrade the one or moreindividual components of the biomass the components of the biomass,particularly the cellulose. The cellulose is in a form substantially thesame as it was naturally as a component of the biomass. Suchfractionation provides a fraction or extracted product that may beseparated from the fractionated or extracted biomass. The pulsation andshear forces avoid altering the chemical characteristics of theindividual components and does not substantially result in thefragmentation of such components. The fractionated or extracted biomassmay be subjected to separation, namely filtration or screening 125 withor without agitation, followed by a compression force 130, and thenfollowed by additional filtration and/or separation with or withoutagitation 140. The fractions may be used to provide a desired productstream 150. In one embodiment, the amount of hemicellulose and sugars inthe fractionated biomass are monitored such as using a brix meter. Ifsignificant hemicellulose or sugars still are present the steps ofsubjecting to high frequency pulses and shear forces and subjecting tocompressive forces may be repeated.

As briefly discussed above, in an initial pretreatment step 90 thebiomass may be pre-soaked and contacted with a solvent such as with analcohol, an aqueous alcohol, water or glycerin or co-solvent or mixturethereof in order to begin the fractionation or extraction of thebiomass, particularly to begin isolating the hemicelloses from thebiomass. The biomass may swell during this pretreatment step 90. Thebiomass may be disassembled 110 such as by chopping, cutting, fraying,attrition or crushing prior to contact with the solvent 100. In aparticular embodiment, if the biomass is, for example, fresh plantbiomass or herbal plant material, the material may be contacted withalcohol. If the biomass is dried plant biomass or herbal plan material,it may be contacted with an aqueous alcoholic solution. This aqueousalcoholic extraction may be performed in aqueous alcohol at differentconcentrations. Suitable alcohols may be short chain alcohol, such as,but not limited to, methanol, ethanol, propanol, isopropanol, butanoland isobutanol. In a particular embodiment, the alcohol is ethanol. Thealcohol may be a co-solvent mixture such as a mixture of an alcohol andwater. The aqueous alcoholic solution may comprise from 0-100% (v/v)alcohol. More particularly, the aqueous alcoholic solution may comprisefrom 25-95% (v/v) alcohol. In a particular embodiment, the aqueousalcoholic solution is 25% (v/v) or more alcohol. In another particularembodiment, the aqueous alcohol may be 60% (v/v) alcohol. In anotherembodiment, the aqueous alcoholic solution may be 70% (v/v) alcohol. Inyet another embodiment, the aqueous alcoholic solution may be 86% ormore (v/v) alcohol. In yet other embodiments, the process forfractionating or extracting biomass may comprise contacting the biomasswith glycerin or an aqueous glycerin solution.

In yet another embodiment, the process for extracting biomass maycomprise contacting the biomass with water via contacting with steam toprovide a 20 to 40 percent moisture gain. Typically, in otherembodiments of the invention, the ratio of biomass/solids contacted witha solvent/liquids used may be 1:1 to 1:10 of solids to liquid. Duringcontact with the solvent (alcohol or water) the fibers of the biomassmay swell.

With respect to disassembling the fibers, the fibers are initiallyopened up by chopping, cutting, fraying, attrition or crushing thebiomass and are thereby provided in a fluidized or flowable form. Forexample, the biomass fibers may be processed in a mechanical highconsistency fluidization machine such as a refiner or disk mill. Anexemplary disk mill is available from Sprout Waldron, Beloit or Andritz.By utilizing a refiner or disk mill, the biomass and particularly thefibrous material thereof may be altered without destroying the fibrousnature of the fibrous material so that the high frequency pulses andshear forces of the fractionation apparatus are accessible to thefibrous material. The processing may take place for any amount of timenecessary as would be understood by one of skill in the art as necessaryto affect this step. In a particular embodiment, the disassembly processis performed for one minute or less.

The overall pretreatment step 90 may take place for any period of timethat is sufficient for the fractionation or extraction process and maytake place in any vessel, container or mixer suitable for contacting thebiomass with a solvent and/or disassembling the fibers. In someembodiments, the pretreatment step may be any length of time between,for example, 15 minutes, 30 minutes or one hour, and 72 hours. Inanother embodiment, the pretreatment step may be 15 minutes or less. Thepretreatment step may be one minute or less. In the pretreatment step,the biomass in contact with the solvent may optionally be subjected to acompressive force, which can facilitate absorption of the solvent intothe biomass. The compression in the pretreatment step 90 may take placeaccording to any technique that will be appreciated by one of skill inthe art. In an embodiment of the invention, compression during thepretreatment step may be affected by a screw press.

In another embodiment, the pretreatment may include the addition of amild acid to prehydrolyze the biomass to facilitate removal of thehemicellulose. Suitable acids for acidifying the pretreatment solution(solvent) include inorganic acids such as nitric acid, hydrochloric acidand phosphoric acids, and organic acids, such as acetic acid or formicacid. It is recognized that the addition of mild acids like acetic acidor formic acid may not be necessary because of natural amounts of thesame being present in the biomass. If acidification/hydrolysis isdesired, the pH of the solution will be about 0.5 to 7.0 and often maybe between about 1.0 to 5.0. A sequestering agent or chelating agentsuch as an aminocarboxylic acid or aminopolyphosphoric acid may also beused.

Additionally a compound to help catalyze delignification may beincluded. In one embodiment, an anthraquinone (AQ) may be utilized.Exemplary anthraquinones and derivatives thereof including1-methylanthrazuinone, 2-methylanthraquinone, 2-ethylanthraquinone,2-methoxyanthraquinone, 2,3-dimethylantraquinone, and2,7-dimethylantraquinone.

In another embodiment an alkaline buffer such as an alkaline metalhydroxide, carbonate, phosphate, or borate may be included to facilitateseparation of the hemicellulose and lignin individual components.Suitable buffers may include sodium hydroxide, sodium carbonate, andsodium borate. Mixtures or blends of the hydroxides, carbonates, andborates may be used. If an alkaline metal hydroxide is added, the pH maybe between about 7.0 to about 13.0 and often may be between about 8.0 toabout 11.0.

The pretreatment step 90 to hydrate or rehydrate the biomass may beconducted at ambient temperature, elevated temperature (20° C. to 90°C.) or using steam/vapor (greater than 100° C.). It is recognized thatthe vapor may be of the solvent.

Isolation or removal of the hemicelluloses may be accomplished at thisstage. Ultrafiltration or diafiltration may be utilized to provide aretentate having 80 to 95 percent of the hemicelluloses of the biomassand a permeate comprising the biomass with a substantial portion of thehemicelluloses removed. It is noted that the retentate may includeisolated organic acids such as acetic acid or formic acid which may beremoved from the retentate and used to pretreat the biomass as describedabove. The hemicelluloses may be dried to avoid fermentation or moldproduction and then used as a raw material for ethanol production, forexample.

Overall the desire is to provide the fibers in a form wherein thecomponents of the fibers can be readily fractionated using the highshear forces and pulses of the fractionation apparatus with asubstantial portion of the hemicelluloses having been removed. Theselection of the conditions of the pretreatment step 90 such as solventchoice, temperature, pressure, time, additives, and the like will bedependent on the biomass and the components of that biomass to befractionated and isolated, and will be within the skill of one in theart without undue experimentation. Extreme and harsh conditions may beavoided so as to not denature and/or degrade the cellulose component.

Following removal of the hemicelluloses 105, the biomass is in fluid orflowable form may be subjected to fractionation 120 to fractionate orextract the biomass using shear forces and pulsation. It will beappreciated that in a particular embodiment, shear forces and pulsationare used in which the components of the biomass are not denatured oraltered, and the chemical properties of the individual components aremaintained wherein a portion of the fractions or extracts may beseparated from the biomass. The subjecting of the biomass to shearforces and high frequency pulses may take place for any amount of timenecessary as would be appreciated by one of skill in the art asnecessary to affect this step. In a particular embodiment, this step maytakes place for one minute or less. In operation the fluidized biomassis rapidly accelerated from about 4 mph to about 120 mph under greaterthan 1000 pulses per second of energy while avoiding attrition of thebiomass particles. This facilitates the ability of the cellularstructure of the biomass to release its various fractions orconstituents from the complex and entangled structure of the biomasswithout having the chemical properties and characteristics of thecomponents being denatured or degraded.

The fractionated biomass material may then be subjected to a compressionforce 130 e.g., a crushing or macerating force optionally in thepresence of additional solvent, wherein the compression force removesliquid fraction for collection while discharging a low liquid solidscake primarily being cellulose. The compression force may be appliedaccording to any technique that is appreciated by one of skill in theart. In a particular embodiment, the compression force is affected byscrews of a screw press that macerate the fractionated biomass and mayinclude optional stirring.

The steps of subjecting to fractionation 120 and subjecting tofractionation can continue until the biomass fraction is substantiallyfree of hemicellulose and sugars. This can be monitored or measured in awide variety of matters including using a brix meter to measure sugarcontent, differential scanning calorimeter (DSC) to measure melttemperatures and differential thermal analysis (DTA) to measure areaunder melt curves.

In one embodiment, the first fractionated biomass may be subjected toconditions to raise the pH of the first fractionated biomass to aboveabout 9. For example, the biomass may be contacted with mild caustic,e.g. 0.1 to 0.5% w/w based upon water, sodium hydroxide.

The fractions or extracts provided according to the present inventionmay be further processed as outlined in FIG. 2. The screened liquids(e.g., liquid fractions) can be contacted with additional biomass, thebiomass disassembled 210, fractionated 220, screened 240, subjected to acompressive force 230, and the solid fractionated biomass primarilybeing cellulosic and the liquid fractionated product stream separated250. It is recognized that although the solid fractionated solid issubstantially cellulose, it still has lignin and some hemicellulosesbound to the cellulose molecules. Not wishing to be bound to a singletheory, Applicant believes that small amounts of hemicellulose allow thelignin to be water soluble and are removed during precipitation.

Once the fractionated biomass is substantially free of hemicellulose andsugars, the biomass is subjected to oxidation at a pH above 7 notingthat the fractionated biomass typically has a pH of about 7 and is about9. In one embodiment, oxidation occurs by contacting the fractionatedbiomass with about 0.1 to about 5 percent hydrogen peroxide. Forexample, with respect to lignin removal, isolation, and purification,the hydrogen peroxide allows the lignin ether bond to cleave.Specifically, the phenolic groups in the lignin are ionized and theresulting radical is mainly of the phenoxyl radical type. Then hydrogenperoxide is formed through dismutation of the superoxide anion. Thesuperoxide anion itself is not very reactive but the decompositionproducts of hydrogen peroxide include the very reactive hydroxylradical. The hydroxyl radical not only reacts with the lignin structuresbut also readily attacks the polysaccharides with subsequent glycosidicbond cleavage and the creation of new sites for peeling reactions. Oncethe perhydoxyl radical attaches to the lignin (or protein or waterinsoluble extractive) these individual components of the biomass becomemore polar and water soluble. Other oxidation agents include alkalimetal peroxides such as organic and inorganic peroxides including sodiumperoxide, calcium peroxide, magnesium peroxide, and sodium percarbonate.Moreover this reaction can be facilitated by inclusion of anthraquinoneor its derivatives or other catalysts in the pretreatment step.

In another embodiment, an oxidation mixture is formulated. The oxidationmixture is provided by mixing together an alkaline buffer such asalkaline metal hydroxide, carbonate, phosphate, or borate, a source ofoxyanions and a short chain organic acid to provide an oxidationmixture. Suitable alkaline buffers include sodium hydroxide, sodiumcarbonate and sodium borate. Suitable sources of oxyanions includehydrogen peroxide and organic and inorganic peroxides such as sodiumperoxide, calcium peroxide, magnesium peroxide, and sodium percarbonate.Optionally, sulfuric acid or sodium sulfate (i.e., a source of S₂ ⁻ orHS⁻ ions) may be included as an oxyanionic nucleophilic sulfide catalystto facilitate delignification. Such will also facilitate base catalyzedesterification and transesterification of the cellulose when used as afeedstock. In one embodiment, the oxyanions may be generatedelectrically by ozonation. Suitable short chain organic acids mayinclude acetic acid (vinegar) and formic acid. A stabilized catalystmixture is provided by mixing together an alkali metal carbonatestabilizer such as sodium carbonate or sodium bicarbonate and amanganese catalyst. An exemplary manganese catalyst is a chelatedmanganese acid such as a manganese amino acid chelate. The stabilizedcatalyst mixture in one embodiment may be in powder solid form.

The stabilized catalyst mixture is then applied to the secondfractionated biomass, for example, by mixing the catalyst in powder formwith the second fractionated biomass. The liquid oxidation mixture isthen added to the second fractionated biomass and mixed, and oxidationis allowed to occur for about one minute to about 48 hours. The oxidizedsecond fractionated biomass is then subjected to compressive force withoptional spinning to provide a third fractionated biomass low in lignin(i.e., often less than about 4 to about 8 percent), and a third liquidfraction high in lignin. The third fractionated biomass may again beoxidized as above and subjected to a compressive force with optionalspinning to provide a fourth fractionated biomass substantially lower inlignin (i.e., often less than about 2 to about 4 percent and a fourliquid fraction substantially high in lignin. The isolating of thebiomass steps and repeated contacting with the oxidation mixturefollowed by compression can be repeated multiple times until thefractionated biomass has less than about 0 to about 2 percent ligninwith the last step(s) being a conventional water rinse step.

After separation, the now water soluble individual components, e.g., thelignin, can be further separated, isolated and/or purified, such asdescribed in copending U.S. application Ser. No. ______, filed Feb. 11,2015 (Attorney Docket No. 1237-4IP2), the disclosure of which isincorporated herein by reference in its entirety. In one embodiment, thecentrifugation is used to provide a decant. Then, for example,ultrafiltration or diafiltration membranes, available from Millipore,Billerica, Mass., may be used. A first membrane can be used to removeany remaining hemicellulose from the liquid fraction. In one embodiment,the first membrane is a 10K dalton screen. The retentate will comprisethe hemicellulose and the permeate will primarily comprise lignins,proteins, and extractives with a small amount of hemicellulose, sugars,and fiber fragments. The second membrane will isolate the lignin,protein or extractive depending on the membrane as a retentate and anyremaining hemicellulose, sugars, fragments, contaminants (e.g., heavymetals) as the permeate. In one embodiment, the second membrane is an 8Kdalton screen. A further 3K dalton screen can be used to further isolatethe desired component. The cellulose may be subjected to based catalyzedesterification or transesterification.

In a particular embodiment, the cellulose and/or cellulose pulp providedby the fractionation and/or extraction process of the present inventioncan be used or applied in the preparation of paper and paper products.Examples of paper products include, but are not limited to: paper;paperboard; and card stock. Use of the paper products prepared from thecellulose and/or cellulose pulp provided by the present invention is notparticularly limited. The paper products can be produced with a widevariety of properties, depending on its intended use, which range from,for example: representing value, such as in paper money, bank notes,checks, security, vouchers and tickets; for storing information, such asin books and notebooks, scrapbooks, magazines, newspapers, art, letters;for personal use, such as in diaries, notes to oneself, etc. and scratchpaper; for communication, such as in communication between individualsand/or groups of people; for packaging and containers, such as inpaperboard, kraft board, containerboard, linerboard, beverage and/orfood containers, liquid containers, corrugated boxes, paper bags,envelopes, wrapping tissue, Charta emporetica and wallpaper; forcleaning, such as in toilet paper, handkerchiefs, paper towels, facialtissue and cat litter; for construction, such as in papier-mâché,origami, paper planes, quilling, paper honeycomb, used as a corematerial in composite materials, paper engineering, construction paperand paper clothing; and other uses, such as in emery paper, sandpaper,blotting paper, litmus paper, universal indicator paper, paperchromatography, electrical insulation paper (see also dielectric andpermittivity) and filter paper.

The method by which the cellulose and/or cellulose pulp provided by thepresent invention is used in the production of paper and paper productsis not particularly limited, and any method that would be appreciated byone of skill in the art may be used in the production of paper and paperproducts using the cellulose and/or cellulose pulp provided by thepresent invention. For example, the cellulose pulp provided according tothe present invention can be fed to a paper machine where it is formedas a paper web and the water is removed from it by pressing and drying.The cellulose pulp provided by the present invention may also bebleached to make the pulp whiter. Typical chemicals and processes usedin the bleaching of pulp include: chlorine; sodium hypochlorite;extraction with sodium hydroxide; oxygen; alkaline hydrogen peroxide;ozones; chelation to remove metals; enzyme treatment; peroxy acids; andsodium dithionite. Typical chelation agents include, but are not limitedto, EDTA and DTPA. Although not particularly limited by the method ofbleaching of the cellulose and/or cellulose pulp provided by the presentinvention, elemental chlorine free (ECF) and/or total chlorine free(TCF) methods of bleaching provide more environmentally friendly methodsof bleaching. TCF bleaching, for example, prevents the formation oftoxic chemicals such as dioxins. An example of a TCF sequence for thebleaching of pulp is wherein the pulp would be treated with oxygen, thenozone, washed with sodium hydroxide then treated in sequence withalkaline peroxide and sodium dithionite.

In other embodiments, the cellulose and/or cellulose pulp providedaccording to the present invention can be used or applied in thepreparation and/or manufacture of paper coatings. Cellulose andcellulose derivatives have been used to coat papers to enhance physicalcharacteristics, for example, but not limited to, appearance, e.g.,glossiness and finish, strength, rigidity and water resistance. Themanner in which the paper coatings prepared from the cellulose and/orcellulose pulp provided according to the present invention is notlimited and the method used may be any that would be appreciated by oneof skill in the art.

In yet other embodiments, the cellulose and/or cellulose pulp providedaccording to the present invention can be used in the preparation offibers. Examples of fibers include, but are not limited to, regeneratedcellulose fibers, for example, cellophane and rayon.

In yet other embodiments, the cellulose and/or cellulose pulp providedaccording to the present invention can be used in consumables. The typeof consumable is not particularly limited, and applications can include,but are not limited to: microcrystalline cellulose or powdered celluloseused as inactive fillers in drug tablets; thickeners and/or stabilizersPowdered cellulose may also be used to improve characteristics ofprocessed foods or foodstuffs, for example, to prevent caking and/orclumping of the processed food or foodstuffs within a container.

In yet other embodiments, the cellulose and/or cellulose pulp providedaccording to the present invention can be used in scientificapplications. Cellulose is commonly used in the laboratory as thestationary phase for chromatography, in particular, thin layerchromatography. Liquid and gel filtration typically use productsprepared from cellulose, either alone or in combination with otherfiltration media, for example, diatomaceous earth. Various filtrationmade may comprise the cellulose of the invention.

In yet other embodiments, the cellulose and/or cellulose pulp providedaccording to the present invention can be used in construction andbuilding materials. Cellulose insulation made from recycled paper isbecoming popular as an environmentally preferable material for buildinginsulation. It can be treated with boric acid as a fire retardant.Moreover, hydrogen bonding of cellulose in water can produce asprayable, moldable material as an alternative to the use of plasticsand resins. The recyclable material can be made water and/orflame-resistant or fire retardant, and can provide sufficient strengthfor use as a building material.

In another embodiment, the cellulose can be treated with celluloseenzymes to hydrolyze the crystalline cellulose to glucose followed byfermentation of the glucose with yeast or suitable microorganism toprovide biofuel and/or bio feedstock. It is recognized that thehemicellulose and/or sugars previously separated from the fractionatedbiomass may be added back to be co-fermented with the cellulose.

In another particular embodiment, fractionation or extraction accordingto the invention provides hemicelluloses and sugars. Sugars and/orhemicelluloses provided by the process according to the invention mayfurther be used in the preparation of biofuels such as, but not limitedto, ethanol or the preparation of polymers/plastics. One such embodimentis the fermentation of the provided fractions to produce the ethanol. Inanother embodiment, the polymer is polylactic acid (PLA). In anotherembodiment the lignin may be further separated and emulsified forfurther processing. Because the lignin has not been subjected to hightemperatures, its functional groups have not chemically reacted and theisolated lignin may be more reactive.

The following example is provided to illustrate the present invention,and should not be construed as limiting thereof.

EXAMPLES Example 1 Wheat Grass

10 Kg of dried wheat grass (straw) is chopped to a stalk length of ¾ to2 inches. The straw was briefly rinsed with cold clean water to removesand and dirt. The wheat straw is then subjected to water or steaminjection into a disk mill for a few seconds to mechanically disassemblethe cellulosic structure. The fluidized wheat grass is then subjected tohigh shear forces for 1.5 to 3 seconds with pulses of 1824 to 912 timeswithout denaturing and/or degrading the components of the wheat straw.The combined mixture is subjected to compressive forces to separate thestream into liquid and a 20-60% cellulosic solids fractions. The liquidfraction containing hemicellulose is retained.

The solid fraction is pretreated with NaOH sufficient to raise the pH ofthe cellulosic water slurry from about 4-7 to 10-12. This basic mixtureis allowed to age from a few seconds to 1 hour and again processedthrough the system starting at the disk mill which is subjected to wateror steam injection in the mill for a few seconds to mechanicallydisassemble the cellulosic structure. The fluidized wheat grass is thensubjected to high shear forces for 1.5 to 3 seconds with pulses of 1824to 912 times without denaturing the components of the wheat straw. Thecombined mixture is subjected to compressive forces to separate thestream into liquid and a 20-60% cellulosic solids fractions. The liquidfraction containing hemicellulose is added to the first and secondfraction and undergoes further processing.

The solid fraction is treated with an oxidation agent hydrogen peroxide,sufficient to raise the pH of the cellulosic water slurry from about10-12 to 8-10. This basic mixture is allowed to age from a few secondsto 1 hour and again processed through the system starting at the diskmill which is subjected to water or steam injection in the mill for afew seconds to mechanically disassemble the cellulosic structure. Thefluidized wheat grass is then again subjected to high shear forces for1.5 to 3 seconds with pulses of 1824 to 912 times without denaturing thecomponents of the wheat straw. The combined mixture is screened andsubjected to compressive forces to separate the stream into liquid and a20-60% cellulosic solids fractions. The liquid fraction containinglignin is retained. The solid fraction is then treated again to raisethe pH and the liquid fraction containing hemicellulose is added to thefirst and second fraction and undergoes further processing. The solidfraction is then treated with an oxidation agent and rerun through thefractionation unit. The liquid fraction containing lignin is added tothe first liquid lignin fraction and further separated using a membrane.

Example 2

423 grams of dry switch grass is steam activated to rehydrate at about25 to 50 percent water in a single disk refiner to provide the switchgrass in a fluidized or flowable condition. Naturally occurringcarboxylic acids (acetic acid and formic acid) with the switch grasslower the pH to below 3. The hydrated/activated switch grass issubjected to compressive force to separate a liquid high inhemicelluloses and a biomass high in cellulose and lignin. Thehemicellulose/liquid is then subjected to a 1 to 5 kD ultrafiltrationmembrane to remove the acetic acid and formic acid as a permeate forreuse in the process.

The biomass is then subjected to high frequency pulses and shear forceswithout denaturing and/or degrading the lignin using the GreenExtraction Technology fractionation apparatus described in U.S.application Ser. No. 14/454,833 filed on Aug. 8, 2014. The biomass isfractionated for about 15 to about 30 seconds at pulses of 912 to 1824to provide a first fractionated biomass and a first liquid fraction. Thefirst fractionated biomass is contacted with 0.3% w:w based upon watersodium hydroxide to raise the pH above about 9. The first fractionatedbiomass is then subjected to compressive force to separate a secondliquid fraction with most of the remaining hemicellulose from a secondfractionated biomass high in cellulose and lignins.

The second fractioned biomass is then subjected to oxidation to separatethe lignin from the cellulose. An oxidation mixture is formed andcomprises 2000 ml of hydrogen peroxide at 3% buffered with 60 g ofsodium hydroxide and 300 ml of acetic acid. A catalyst/stabilizermixture is formed by mixing 2 g of sodium carbonate stabilizer and 15 mgof manganese amino acid chelate catalyst in powder form. The powderedcatalyst/stabilizer mixture is applied to the second fractionatedbiomass and then it is contacted with the liquid oxidation mixture andoxidized for 60 minutes. The oxidized second fractionated biomass issubjected to compressive forces using a two screw press with stirring toprovide a third fractionated biomass high in cellulose with a lignincontent of less than 7% and a third liquid fraction high in watersoluble lignin. The third fractionated biomass is then oxidized againfor 60 minutes using 1500 ml hydrogen peroxide and the same amounts ofthe other components of the oxidation mixture and thecatalyst/stabilizer mixture. The oxidized third fractionated biomass isthen subjected to compressive forces to provide a fourth fractionatedbiomass high in cellulose with a lignin content of less than 7% and afourth liquid fraction high in lignin. The entire oxidation process isthen repeated using 1000 ml hydrogen peroxide oxidized for 120 minutesand then subjected to compressive force to provide a fifth fractionatedbiomass high in cellulose having a lignin content of less than 5%.

DSCs of a third fractionated biomass are provided in FIGS. 3A and 3B,noting that FIG. 3B illustrates that the cellulose has been acetylateddue to the presence of acetic acid.

Example 3

423 grams of dry wheat straw is steam activated to rehydrate at about 25to 50 percent water in a single disk refiner to provide the switch grassin a fluidized or flowable condition. Naturally occurring carboxylicacids (acetic acid and formic acid) within the wheat straw lower the pHto below 3. The hydrated/activated wheat straw is subjected tocompressive force to separate a liquid high in hemicelluloses and abiomass high in cellulose and lignin. The hemicellulose/liquid is thensubjected to a 1 to 5 kD ultrafiltration membrane to remove the aceticacid and formic acid as a permeate for reuse in the process.

The biomass is then subjected to high frequency pulses and shear forceswithout denaturing and/or degrading the lignin using the GreenExtraction Technology fractionation apparatus described in U.S.application Ser. No. 14/454,833 filed on Aug. 8, 2014. The biomass isfractionated for about 15 to about 30 seconds at pulses of 912 to 1824to provide a first fractionated biomass and a first liquid fraction. Thefirst fractionated biomass is contacted with 0.3% w:w based upon watersodium hydroxide to raise the pH above about 9. The first fractionatedbiomass is then subjected to compressive force to separate a secondliquid fraction with most of the remaining hemicellulose from a secondfractionated biomass high in cellulose and lignins.

The second fractioned biomass is then subjected to oxidation to separatethe lignin from the cellulose. An oxidation mixture is formed andcomprises 2000 ml of hydrogen peroxide at 3% buffered with 60 g ofsodium hydroxide and 300 ml of acetic acid. A catalyst/stabilizermixture is formed by mixing 2 g of sodium carbonate stabilizer and 15 mgof manganese amino acid chelate catalyst in powder form. The powderedcatalyst/stabilizer mixture is applied to the second fractionatedbiomass and then it is contacted with the liquid oxidation mixture andoxidized for 60 minutes. The oxidized second fractionated biomass issubjected to compressive forces using a two screw press with stirring toprovide a third fractionated biomass high in cellulose with a lignincontent of less than 7% and a third liquid fraction high in watersoluble lignin. The third fractionated biomass is then oxidized againfor 60 minutes using 1500 ml hydrogen peroxide and the same amounts ofthe other components of the oxidation mixture and thecatalyst/stabilizer mixture. The oxidized third fractionated biomass isthen subjected to compressive forces to provide a fourth fractionatedbiomass high in cellulose with a lignin content of less than 7% and afourth liquid fraction high in lignin. The entire oxidation process isthen repeated using 1000 ml hydrogen peroxide oxidized for 120 minutesand then subjected to compressive force to provide a fifth fractionatedbiomass high in cellulose having a lignin content of less than 5%.

The wheat straw fractionated biomass was analyzed for percent lignincontact, Kappa number, and fiber quality. The results are provided inTable 1.

TABLE 1 Fiber Quality Analyzer (FQA) - Acid Insoluble Lignin, % FiberAnalysis Pulp Sample Test 1 Test 2 Avg. Kappa # Length Fines Kink CurlCoarseness Wheat 5.19 5.15 5.17 33.52 0.667 19.93 2.25 0.128 0.097 Straw

Example 4

Example 3 was repeated with wild oats. The wild oats fractionatedbiomass was analyzed for lignin contact and Kappa number. The resultsare provided in Table 2.

Acid Insoluble Lignin, % Pulp Sample Test 1 Test 2 Avg. Kappa # WildOats 3.12 3.37 3.25 22.11

Example 5

Example 2 is repeated except the oxidized fifth fractionated biomass issubjected to oxidation using 1000 ml hydrogen peroxide again. This pulpis then combined with Northern bleached softwood kraft (“NBSK”) at a 80percent pulp of the invention/20 percent NBSK blend to which is added 8percent calcium carbonate. This is made into paper to mimic ink jet typepapers.

Example 6

Example 3 is repeated except the oxidized fifth fractionated biomass issubjected to oxidation using 1000 ml hydrogen peroxide again. This pulpis then combined with Northern bleached softwood kraft (“NBSK”) at an 80percent pulp of the invention/20 percent NBSK blend to which is added 8percent calcium carbonate. This is made into paper to mimic ink jet typepapers.

Table 3 provides testing against commercially available ink jet paperfor paper made according to Examples 5 and 6.

TABLE 3 Stiffness Tensile Tensile Gloss Porosity Thickness (gram- TearBurst (DRY) (WET) Abrasion Fold @60 (coresta Opacity Brightness(microns) force) (gram-force) (psig) (kg/15 mm) (g/15 mm) (strokes)(cycles) (%) units) (%) (%) Control 237 870 64 5 2.0 160 1 2 4.6 3461 9386 (repulped commercial ink jet paper) A 80% 189 1039 78 30 6.0 300 8 464.6 451 93 80 Switchgrass/ 20% NBSK (+8% CaCO3) B 80% Wheat 184 968 7627 4.7 250 8 29 4.6 534 93 78 Straw/20% NBSK (+8% CaCO3) C

This shows that the papers of the invention have significantly higherstrength and toughness as compared to the control paper due to theavoidance of denaturing and/or degrading the cellulose using the processof the invention.

Although selected embodiments of the present invention have beendisclosed for illustrative purposes, those skilled in the art willappreciate that various modifications, additions and substitutions arepossible, without departing from the scope and spirit of the inventionas disclosed in the accompanying claims.

That which is claimed is:
 1. A process for providing cellulose isolatedfrom a biomass, the process comprising: a) pretreating the biomass; b)subjecting the pretreated biomass to high frequency pulses and shearforces without denaturing and/or degrading the individual components ofthe biomass; c) subjecting the biomass to compressive force to separatea first liquid fraction from a first fractionated biomass; d) subjectingthe first fractionated biomass to conditions to raise the pH above 9 andthen subjecting the biomass to the same high frequency pulses and shearforces of step b); e) subjecting the first fractionated biomass tocompressive forces to separate a second liquid fraction from a secondfractionated biomass wherein the second fractionated biomass issubstantially devoid of hemicelluloses and sugars; f) subjecting thesecond fractionated biomass substantially devoid of hemicelluloses andsugars to oxidation at a pH above 7; and g) subjecting the secondfractionated biomass to compressive forces to separate one or more watersoluble components from the second fractionated biomass to provide athird fractionated biomass comprising cellulose that is substantiallydevoid of hemicellulose, sugar, and lignin.
 2. The process of claim 1,further comprising after step e): subjecting the second fractionatedbiomass again to conditions to raise the pH above 9 and subjecting thesecond fractionated biomass to compressive force to separate one or morewater soluble components from the second biomass biomass.
 3. The processof claim 1, wherein the steps are conducted at ambient temperature toabout 60° C.
 4. The process of claim 1, further comprising after g): h)subjecting the third fractionated biomass to oxidation at a pH above 7;and i) subjecting the third fractionated biomass to compressive forcesto separate one or more water soluble components from the biomass toprovide a fourth fractionated biomass comprising cellulose that issubstantially devoid of hemicellulose, sugar, and lignin.
 5. A cellulosehaving less than 7 percent lignin that has not been denatured and/ordegraded by extreme temperature, pressure or chemical conditions.
 6. Acellulose having less than 7 percent lignin that has not been denaturedand/or degraded by extreme temperature, pressure or chemical conditionsprepared by the process of claim
 1. 7. A paper or paper product preparedfrom the cellulose of claim
 5. 8. A process for providing celluloseisolated from a biomass comprising subjecting a biomass to conditions toseparate cellulose from the biomass to provide a fraction comprisingcellulose and lignin without denaturing or degrading the cellulose andthen oxidizing the fraction to provide cellulose having less than 7percent lignin.